New Publication: Genital interactions during simulated copulation among marine mammals

CT Reconstructions of marine mammal penises inside vaginas. Images are rendered in sagittal plane for short-beaked common dolphins (D. delphis; top) and harbour seals (P. vitulina; bottom). Two-dimensional volume reconstructions on the left use sharp lung and smooth soft tissue algorithms. Three-dimensional volume renders on the right show erectile tissue in red and non-erectile tissue as transparent.

“We investigated the mechanics of copulatory interactions in marine mammals to determine how morphological diversity of genitalia correlates with function during simulated copulation. The excised penises of deceased male cetaceans and pinnipeds were distended, positioned inside the vaginas of females from the same species, and CT-scanned in situ using diceCT techniques. We found evidence of both congruent and antagonistic genital coevolution between the sexes, depending on the species. Sexual selection forces contribute to the extensive genital morphological variation observed in male and female marine mammals.”